Last week, the labor union UNITE HERE, which represents mostly service workers, issued a demand to the Democratic Party. UNITE HERE wanted Cleveland and Charlotte, N.C., two of the sites being considered for the 2012 Democratic National Convention, ruled out because the cities didn’t have enough unionized hotels.

DemConWatch, an online blog, said conventions have been won or lost based on the issue. In one posting, the blog suggested the city of Charlotte is proud not to have any union hotels, and pointed to a “Visit Charlotte” spokesperson’s push to attract the DNC, which included the fact that Charlotte has non-union hotels. …

Democrats have not officially responded, but Dr. David Swindell, director of UNC Charlotte’s Public Policy Degree Program, says they’re probably not taking this lightly.

“It’s a core constituency of the Democratic Party so of course they’re going to be interested in something like that,” Swindell says.

Labor unions spent at least $171.5 million on the 2010 elections. They were by far the Democrats’ biggest sources of money, and their money undoubtedly helped stem some of the potential electoral damage. Now Democrats owe organized labor big time.